fix the way to get API Key

assemblyai_audio__transcript_tool.py

@@ -1,3 +1,4 @@
+import os
 from langchain_community.document_loaders import AssemblyAIAudioTranscriptLoader
 from smolagents import Tool
 
@@ -21,7 +22,7 @@ class AssemblyAIAudioTranscriptTool(Tool):
         """
         loader = AssemblyAIAudioTranscriptLoader(
             file_path=url,
-            api_key=userdata.get("ASSEMBLYAI_API_KEY")
+            api_key=os.getenv("ASSEMBLYAI_API_KEY")
         )
         document = loader.load()
         return document[0].page_content